Control system for power transmission unit of vehicle

Abstract

A control system for a power transmission unit of a vehicle transmitting power outputted from a prime mover, comprising: a resonance detecting / predicting device for detecting or predicting a generation of a resonance of the power transmission unit resulting from a power transmission; a driving condition detecting device for detecting a driving condition of a vehicle in case the generation of a resonance is detected or predicted by the resonance detecting / predicting device; and a resonance dampening control selecting device for changing contents of a control for dampening the detected or predicted resonance on the basis of the driving condition of the vehicle detected by the driving condition detecting device.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates generally to a system for controlling a power transmitting condition of a power transmission unit mounted on a vehicle, and more particularly, to a control system for dampening a resonance resulting from a transmission of power.[0003]The disclosure of Japanese Patent Application No. 2006-053622 filed on Feb. 28, 2006 including specification, drawings and claims is incorporated herein by reference in its entirety.[0004]2. Related Art[0005]An internal combustion engine such as a gasoline engine is conventionally used as a prime mover of a vehicle, and a power transmission system for transmitting a power to a driving wheel is composed mainly of a speed change mechanism. As a speed change mechanism, a geared transmission varying a speed change ratio stepwise, and a continuously variable transmission varying a speed change ratio continuously are widely known. Additionally, in recent years, an apparatus...

AI Technical Summary

Benefits of technology

[0012]Therefore, when a resonance resulting from the power transmission is detected or predicted, the contents of the resonance dampening control is selected in accordance with the driving condition. For this reason, an excessive vibration of the power transmission unit and a resultant augmentation of a stress can be suppressed. Consequently, vibrations and noises in the vehicle are dampened entirely, and durability of the power transmission unit can also be improved.

[0013]Preferably, in addition to above, the power transmission unit comprises a clutch mechanism capable of changing a transmission torque capacity thereof, and the first resonance dampening control includes a control for reducing the torque capacity of the clutch mechanism, thereby the resonance can be dampened by controlling the clutch mechanism such as a clutch and a brake, and this makes the control easy.

[0016]Therefore, a plurality of resonance dampening controls are carried out according to priority. For this reason, the resonance can be dampened effectively. Moreover, an appropriate resonance dampening control can be carried out according to a condition of the vehicle, therefore, the durability of the vehicle can be improved.

[0017]Preferably, in addition to the above, the power transmission unit comprises a clutch mechanism capable of changing a transmission torque capacity thereof, and the resonance dampening control device includes a device for carrying out a control of reducing the torque capacity of the clutch mechanism as a priority resonance dampening control, thereby the resonance is dampened by controlling the clutch mechanism such as a clutch and a brake on a priority basis. For this reason, the resonance is dampened easily and effectively.

[0018]Preferably, in addition to the above, the prime mover includes an internal combustion engine capable of changing an operating point thereof governed by an output torque and a revolution frequency or momentums corresponding to those factors; the power transmission unit includes at least any of a clutch mechanism, a transmission capable of varying a speed change ratio, and a differential mechanism performing a differential action selectively among at least three elements; and the control for dampening resonance is at least any of a control for reducing the torque capacity of the clutch mechanism, a control for changing an operating point of the internal combustion engine, a control for varying the speed change ratio, and a control for activating the differential mechanism in an inactive condition, thereby the resonance is dampened by controlling the mechanisms for transmitting the power to change the operating conditions thereof. For this reason, the resonance dampening control can be carried out easily.

[0019]Preferably, in addition to the above, the power transmission unit includes an electrical transmission part in which a ratio between the revolution frequencies of the input side and the output side is varied continuously by electrically controlling a torque to be established or absorbed, and a mechanical transmission part in which a ratio between the revolution frequencies of the input side and the output side is varied by changing a transmission route of the torque, thereby the resonance of a hybrid vehicle resulting from its running is dampened, therefore, riding comfort and durability of the vehicle are improved.

Problems solved by technology

Moreover, no small clearance should exist in some part of the power transmission line and this causes a chattering.

Further, a road surface is bumpy and not always flat, therefore, the torque inputted from a driving wheel side also fluctuates periodically.

Images